From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagi Grimberg Subject: Re: [PATCH 2/9] IB: add a proper completion queue abstraction Date: Sun, 22 Nov 2015 16:57:23 +0200 Message-ID: <5651D7D3.7030509@dev.mellanox.co.il> References: <1447422410-20891-1-git-send-email-hch@lst.de> <1447422410-20891-3-git-send-email-hch@lst.de> <564B697A.2020601@sandisk.com> <564C2F01.6020407@dev.mellanox.co.il> <564CC15E.7030602@sandisk.com> <20151120101644.GC24298@lst.de> <564F4F38.9040505@sandisk.com> <56519011.6060204@dev.mellanox.co.il> <20151122101308.GA12189@lst.de> <56519A90.5010502@dev.mellanox.co.il> <20151122132352.GA14154@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20151122132352.GA14154-jcswGhMUV9g@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Christoph Hellwig Cc: Bart Van Assche , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "axboe-b10kYP2dOMg@public.gmane.org" , "linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org >> >> I think that bart wants to allow the caller to select cpu affinity >> per CQ. In this case ib_alloc_cq in workqueue mode would need to >> accept a affinity_hint from the caller (default to wild-card >> WORK_CPU_UNBOUND). > > Hmm, true. How would be set that hint from userspace? I'd really prefer > to see a practical justification for it first. In order to assign CPUs from user-space we'd need an ethtool like interface for isert/srpt/. Given that this is something we don't want to get into right now, I assumed that Bart meant that srpt would take a "least used" approach from srpt driver (which isn't better taking the wild-card option I'd say), So I'll let Bart answer... -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752283AbbKVO5a (ORCPT ); Sun, 22 Nov 2015 09:57:30 -0500 Received: from mail-wm0-f48.google.com ([74.125.82.48]:36190 "EHLO mail-wm0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132AbbKVO51 (ORCPT ); Sun, 22 Nov 2015 09:57:27 -0500 Subject: Re: [PATCH 2/9] IB: add a proper completion queue abstraction To: Christoph Hellwig References: <1447422410-20891-1-git-send-email-hch@lst.de> <1447422410-20891-3-git-send-email-hch@lst.de> <564B697A.2020601@sandisk.com> <564C2F01.6020407@dev.mellanox.co.il> <564CC15E.7030602@sandisk.com> <20151120101644.GC24298@lst.de> <564F4F38.9040505@sandisk.com> <56519011.6060204@dev.mellanox.co.il> <20151122101308.GA12189@lst.de> <56519A90.5010502@dev.mellanox.co.il> <20151122132352.GA14154@lst.de> Cc: Bart Van Assche , "linux-rdma@vger.kernel.org" , "axboe@fb.com" , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" From: Sagi Grimberg Message-ID: <5651D7D3.7030509@dev.mellanox.co.il> Date: Sun, 22 Nov 2015 16:57:23 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151122132352.GA14154@lst.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> >> I think that bart wants to allow the caller to select cpu affinity >> per CQ. In this case ib_alloc_cq in workqueue mode would need to >> accept a affinity_hint from the caller (default to wild-card >> WORK_CPU_UNBOUND). > > Hmm, true. How would be set that hint from userspace? I'd really prefer > to see a practical justification for it first. In order to assign CPUs from user-space we'd need an ethtool like interface for isert/srpt/. Given that this is something we don't want to get into right now, I assumed that Bart meant that srpt would take a "least used" approach from srpt driver (which isn't better taking the wild-card option I'd say), So I'll let Bart answer...